Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Regulating piano making it feel heavier?

Hey team,

I just finished regulating my upright Weinbach for the first time, although I left one octave untouched for the sake of comparison, which I will finish once I’m happy with the settings.

Overall I’m happy with the results, but I’ve noticed the action has gotten noticeably stiffer and heavier, and I’m wondering what tweaks I could make to lighten it a bit.

During regulation, most of the changes were small tweaks to bring things back in line, since they’d obviously drifted out over time. The overall settings seemed pretty good.

The only big & consistent changes I made were:

• Leveling the keys - raising the lowest to match the highest
• Increasing the keydip to bring the aftertouch to about 4/100 of an inch
• Decreasing the hammer backstop distance

The other big parameters (lost motion, letoff distance, etc) are either untouched, or just tweaked a tiny amount to make them more even.

I’m confident it’s not an issue with lubrication or tight pins or any overall issue with the action, since the unregulated keys are consistently lighter than the regulated ones, and I didn’t touch any pins, etc.

The damper spoons could definitely be adjusted to lighten the touch (they’re a little early right now), but I want to understand what’s happening here before I make additional changes!

I’m wondering which things I’ve done might be responsible for this heavier feeling?

If I was to guess, I’d say the aftertouch is the culprit, but from what I understand I’ve reduced the aftertouch (adding punchings) which should in theory make it feel lighter, not heavier.

Would love some advice!

In sorry, I decreased the keydip, not increased.

Added punchings to bring aftertouch to 4/100 inch (using a feeler gauge under the pinching), which ended up being a pretty even 7/16” keydip.

What’s the touchweight on the newly regulated sections vs previously?

When lost motion is eliminated in an upright action, the touch resistance rises because the jack springs are more compressed and thus "stronger" at the start of key motion than they were when there was lost motion.

The OP states that lost motion has not been significantly changed.

7/16" strikes me as a lot of key dip. The after-touch measuring method described is what I would use with a grand action, but my approach with an upright action is quite different. A significant portion of the "bump" we feel in the grand action comes from the engagement of the repetition spring at mid-keystroke, and that element is completely missing in the upright. I understand the priority in regulating an upright action, when it comes to after-touch, is to ensure that there is just enough jack clearance from the hammer butt surface that the hammer does not bobble. With the key held gently against the front rail punching, and the hammer in check at the target distance, the jack should just be leaving the surface of the buckskin. A little more deliberate pressure should open up a small amount of a clearly visible gap between the jack and the hammer butt buckskin. If greater or lesser keydip is desired, the hammer blow needs to be adjusted accordingly, but the relationship of the jack to the hammer butt buckskin at end of stroke should remain the same.

Two significant elements in action stiffness in an upright are the timing of the dampers, and the strength of their springs.

Dampers should begin to lift when the hammers are about halfway to the strings. Once the dampers have been regulated so that damper lift is even with the pedal, individual spoons can be bent to achieve the appropriate lift from the key.

Damper springs need to be strong enough to provide secure damping, but not too strong. I have a tool by Keith Bowman that allows you to rest a measured amount of weight on the point where the damper wire enters the wooden damper lever, with the action lying down on the work bench with the damper surfaces facing up. The tool is designed to let you choose between about 75 grams for the bass dampers, and about 60 grams for the treble dampers. Resting the weight of the tool on the point described above should cause the damper to just begin to move. The spring can be manipulated for more or less resistance. I have been pleased with the results of working to these specs.

Why not try reversing the steps one by one on a key or two to fìnd out?

If you raised the keys, you have raised them on all three levels, meaning that you have raised the height of your capstans by raising the keys. This means you decreased the lost motion and might have completely eliminated it, even though you did not touch capstans. No/less lost motion means your fingers feel the weight immediately and not gradually (as with lost motion) which makes it feel heavier.

I would remove the hammer rest rail and adjust all the hammer shanks in one horizontal line by adjusting capstans (hammerbutt rests on the jack, no lost motion). Than I would screw back the rest rail and insert something (paper, cardboard) to reduce the blow distance just a hair. This will lift all the butt consistently and evenly from all jacks and everything will feel even.
It greatly helped my petrof.
What year/model is your Weinbach?

I am not a tuner/technician, just have been tweaking my upright for fun. Take the advice with grain of salt.

Point well taken, Ian, on the relationship of key raising to lost motion.

This did the trick.

There were two issues. Firstly, as someone suggested, when I leveled the keys I reduced the lost motion. It’s only a small amount, but it makes a surprising difference to the feeling.

Secondly (I just redid my measurements, pardon the bad numbers earlier) in order to bring the aftertouch to 4/100s, I (more or less) reduced the keydip from a slightly uneven 7/16s to an even 3/8s, which seems reasonable to me.

For some reason, when the keydip is less, the key overall feels more stiff. I think it’s because (with lots of aftertouch) the key sort of “releases” towards the end of motion, which makes it feel somehow lighter.

Thinking about it, I think the “stiffer” action is actually a more responsive action with less wasted movement (in lost motion and aftertouch), so I’ll keep it, and adjust the damper spoons to lighten the feel from here.

The dampers are engaging much too early, so there’s plenty of room to experiment with that.

Overall the regulated keys are working much better, no more bobbling, and the jack heads are returning nicely even when I release a key super slowly.


1964, but I don’t know the model. Honestly I’m very impressed - this machine is much older than me, but when I regulated according to spec everything has been just “clicking into place”

I had a 1971 weinbach which was delightful in terms of action - the most even upright I have encountered. I regret selling it.

Decreasing the blow distance can reduce the key dip needed to clear the hammer butt.

I've always wonder why more or less key dip is desired, why is 10.1 or 10.3mm the magic number. why not 11 or 12 ?

Too much key dip makes it harder to play quickly, and is likely to be harder on the hands, other things being equal.

I’ve got it all figured out! The piano is playing much, much better than it did when I bought it.

So far, my only issue is that the damper spoons are a little more uneven than I’d like. But I don’t have a spoon bender, so I had to tweak them by removing the action, making changes, putting it back in, taking notes, and repeating, which was incredibly tedious.

I’m in NZ and getting hold of a damper spoon bender isn’t easy. Does anyone know of a workaround?

I've just been doing exactly the same thing without a spoon bender but rather than taking notes I've been putting chalk marks on the dampers. On the left for early on the right for late. 2 marks for a large adjustment needed. It's still very tedious but maybe easier than taking notes and having to count dampers all the time.

I couldn't get a spoon bender either. The main UK suppliers are out of stock. I've ended up ordering one from the US but it's cost me far too much and it's taking an age to get here.

My dampers and keys are all labeled! But this is basically what I’ve been doing. It’s just hard to know exactly how far a given adjustment is going to “take” until I’ve put the action back in - sometimes I bend the spoon a little and it moves a lot, sometimes I bend it a lot but it springs back and only moves a little.

I just recently did what you are going through with spoons.
I bought a spoon bender, however, I found it extremely clumsy. I could never find the spoon with it with action in place and even when I found, I could not get a feel of how much to bend. So instead I used a plier with thin head.

What I did was the following:
When you take out an action and put it on the surface you will see that the dampers are already touching the spoons - the damper levers are resting on the spoons (this is because the damper spring pushes the damper until it can - till it meets the spoon). When the action is installed in the piano, dampers are pushed against the strings and the damper levers are lifted from the spoons - the gap is created between the damper lever and the spoon. That's why when you press the key, the damper engages only when the spoon touches the damper lever.
So, if you want all the dampers behave in the same way, these means that, when all damper levers are in contact with the damper spoons when the action is taken out, all dampers should be in parallel line. So if you adjust all the spoons, so that when the action is taken out, the dampers are one long very parallel line, you will have them behave the same way. So this means you can take out the action and do it on the floor, table, etc with small pliers.

There is one thing to take into consideration though. The above applies to the scenario, when all the damper screws are equally regulated. If not, you have to regulate them first.
For this, when the action is take out, put some books under the damper lift, or anything really to simulate pushing the pedal - in other words lift up the dampers. When the dampers are lifted, regulate the screws so that all the dampers are in parallel line. After doing this, only then can you regulate the damper spoons with above mentioned technique.

This technique will not work, if someone has messed with your dampers and instead of regulating spoons/screws they just bended the damper wires.

Again, I am not a tuner/technician and wait if someone approves this technique. Also, I am not an english speaker, but I hope you will be able to understand what I wrote.

I;ve never mastered spoon bending tools - either the crooked one, or the flat profile L-shaped one. I just use the "Damper Regulator - Straight" that fits in the combination handle: https://www.fletcher-newman.co.uk/index.php?l=product_detail&p=261

I tilt the action towards me, still in its support cups, hold the end of the wippen and reach in to the spoon from the side, to bend it carefully.

As I said elsewhere, bend it too far forward, then hold the top of the damper lever as you press the key to bend it back to the right position.

This, alas, is not wise with my particular piano. To get the spoon to bend I have to apply enough force that I could easily damage the action if something slipped.

I do the same but use the 45 degree regulator.